According to data from Climate Central, across all the Great Lakes the annual maximum ice cover is, on average, 22% lower than it was a half-century ago. Furthermore, ice coverage is becoming less reliable, with more frequent years of extremely low ice coverage. Based upon ice coverage charts from the NOAA Great Lakes Environmental Research Lab in Ann Arbor, ice cover on the five Great Lakes peaked at an average of 47% this winter (with shallow Lake Erie skewing the numbers upward with its 80% ice coverage…the other four Great Lakes all peaked at or below 50% ice cover). This compares to an average ice cover for all five lakes of 53% in the 1973-2020 time period. AdMore information: Great Lakes Ice Coverage is ShrinkingRelated: